CHAPTER V. 



THE next Order which comes under review is the Diptera, 

 which includes all the two-winged insects, and constitutes 

 a most extensive Order in respect to the number of distinct 

 species. When, however, the numbers of individuals of the 

 same species are considered, it is probable that this Order 

 includes a greater proportion of the insect-world than all the 

 others put together. The preponderance of these insects 

 over the rest holds good with greater force in New Zealand 

 than in many other countries, and this fact may be almost 

 inferred from the large number of spiders present here, which 

 are chiefly dependent on Diptera for their support. The 

 important function of clearing away refuse matter is almost 

 entirely performed by the members of this Order, as the 

 Necrophagous Coleoptera and other scavengers which exist 

 in such large numbers in many countries are practically 

 absent here, and their work consequently devolves upon 

 dipterous insects. 



Group NEMOCERA. 

 Family CULICIM). 



Culex iracundus (Plate IV., fig. i, la larva, ib pupa). 

 The mosquito is only too familiar to every one from 



